Watford’s Carabao Cup hopes are over for another season but only after Tottenham Hotspur needed penalties to progress to the fourth round following a 2-2 draw at the end of 90 minutes.

After the Hornets had taken the lead at the start of the second half through Isaac Success, a Dele Alli penalty – after Christian Kabasele had been controversially sent off – and a quick-fire second from Erik Lamela looked to be sending the home side through at their for-one-night-only temporary Stadium MK home.

But Watford refused to give in and equalised at the death through Etienne Capoue's deflected strike to take the tie to spot-kicks.

The Hornets substitute was first to miss from 12 yards though, and when Domingos Quina also saw his spot-kick saved by Paulo Gazzaniga, Alli fired home to send Spurs through 4-2 from 12 yards.

Javi Gracia, as expected, made wholesale changes from the team which drew 1-1 at Fulham on Saturday, but only one from the team which knocked out Reading in the last round with Craig Cathcart replacing the injured Sebastian Prodl.

Mauricio Pochettino also opted to change his starting XI around en masse, with just Gazzaniga, Toby Alderweireld and Lucas Moura remaining from the team which started the 2-1 victory at Brighton & Hove Albion in what looked a stronger line-up on paper.

With fans still streaming into the ground after kick-off because of problems on road and rail, Spurs had most of the early possession and they won the first corner of the match when Ben Wilmot did very well to track back more than half the length of the pitch to cover Alli as he tried to break down the left.

Heurelho Gomes, making his 150th Watford appearance against his former club, was called into meaningful action for the first time in the 10th minute to hold a low Serge Aurier cross after he had been picked out by a sweeping Alderweireld ball out from the back.

There were some promising signs from the visitors early on though; Nathaniel Chalobah and Quina looking confident in the centre of the park, with the Hornets seeking to use the width of the pitch to kick-start attacks.

Spurs continued to the bulk of the pressing though, and they created an opportunity in the 22nd minute when Aurier, who was finding plenty of space on the right, played in Moura and he spun to strike a low delivery across the six-yard box but Alli was unable to get on the end of it at the far post.

Soon after a ball over the top had the Hornets defence in trouble as Erik Lamela latched on to it but Gomes was swiftly off his line to smother and the ball rebounded away off Moua.

Watford’s response was to have their first effort on target of the night; Success not causing Gazzaniga any undue concerns with a strike from the edge of the 18-yard box.

Marc Navarro then chanced his arm as he ventured forward and came inside before hitting a left-footed shot from 25 yards which Gazzaniga held beneath his crossbar.

The Hornets were having a reasonable spell and following an admittedly slowly-taken corner, the ball was worked back to Navarro, who hit one with his right foot on this occasion but from 30 yards, with the strike going narrowly over.

A lapse in the Tottenham defence then allowed Success to turn inside on the edge of the box and play the ball to Ken Sema, but Aurier made a fine covering challenge as the Sweden international prepared to pull the trigger.

The game then reverted to Spurs having more of the ball, before Navarro hit his third long-range effort of the opening period, as a half of few clear chances ended goalless.

But it wasn’t to stay that way for much longer at the start of the second period when Watford made the breakthrough.

Kiko Femenia was the supplier, laying a pass inside to Success, who was goal-side of his man, but his chance looked like it might have gone after taking a touch and being pushed a bit wide. However, the Nigerian striker showed his strength to hold off Aurier and slam a shot past Gazzaniga to make it 1-0.

Femenia then had a chance of his own four minutes later when he worked a one-two with Chalobah, who back-heeled the ball back into his path but the Spaniard’s shot was comfortable for the Tottenham keeper.

Watford were the more composed and collective side but a lapse nearly let in their opponents in the 56th minute when Moussa Sissoko was able to lift a pass through to Alli in the area, but the captain was unable to keep his effort down.

Soon after Aurier’s pull back from the right fell ideally for Sissoko in the middle of the area, but his right-footed effort was blocked by the body of Adrian Mariappa.

Spurs had improved since going behind but Pochettino had seen enough by the order as Mousa Dembele and Heung-min Son were ordered back from warming order to get ready to come on. Sissoko and Victor Wanyama were the players to make way in the 64th minute.

Gracia made his first change four minutes later as Will Hughes came on for Femenia before the Spurs boss played his final card as Fernando Llorente replaced Moura.

And it was the former Swansea City striker who had Tottenham’s next chance soon after coming off the bench when he headed an Aurier cross over from six yards.

That was an anxious moment for the Hornets defence but it was the Spurs back-line’s turn to escape an even closer call moments later when Hughes robbed an opponent and accelerated to the right side of the area where he tried to set up Chalobah, but the ball broke for the unmarked Sema at the far post, only for him to get his attempted hooked finish all wrong.

However, Spurs must have thought they’d equalised in the 76th minute when the ball was worked to Son on the left side of the area and he drove a shot beneath Gomes, but Wilmot anticipated the danger and got back on the line to clear.

Kabasele came on for Navarro, who looked to be suffering with cramp, but the Belgian international’s involvement in the game was to prove very shortlived.

The defender was caught on the wrong side when Alli was played through on goal and when he went to ground, referee Lee Mason deemed the challenge not only worthy of a penalty but also a red card.

Gomes guessed the right way from the spot, but Alli’s penalty was low to his right in the corner and found the back of the net to equalise.

By this stage though, Tottenham were also down to 10 men after Aurier limped out of the contest and with all three substitutes already on the pitch.

Capoue came on for Sema as Gracia attempted to shore things up, but Spurs sensed their opportunity and were to capitalise on the counter when Dembele raced clear on the right and centred for Lamela to beat the onrushing Gomes and make it 2-1.

But if Spurs thought they were home and dry they were in for a nasty shock.

The Hornets attacked down their left with Success and he accelerated into the area before playing the ball across to Hughes, who laid it back into the D where Capoue hit a right-footed shot that was deflected off Ben Davies and wrong-footed Gazzaniga to equalise and send the tie to penalties.

Success was first up for the Hornets and confidently dispatched his effort, with Son doing likewise. The momentum then swung to Spurs as Capoue saw his penalty saved and Lamela capitalised to make it 2-1.

Hughes restored parity, but Lorente kept Tottenham’s noses in front with a right-footed strike that rose into the roof of the net.

But the Hornets’ hopes were to end when Quina went to Gazzaniga’s right with the same outcome as Capoue and Alli fired home to confirm Tottenham’s place in the fourth round with a 4-2 spot-kick success.

Tottenham Hotspur: Gazzaniga; Aurier, Alderweireld, Sanchez, Davies; Winks, Wanyama (Dembele 64); Sissoko (Son 64), Alli, Lamela; Lucas (Llorente 70). Subs not used: Whiteman, Dier, Walker-Peters, Foyth.

Watford: Gomes; Navarro (Kabasele 77), Mariappa, Cathcart, Masina; Femenia (Hughes 68), Wilmot, Chalobah, Quina, Sema (Capoue 84); Success. Subs not used: Dahlberg, Gray, Holebas, Pereyra.

Bookings: Kabasele sent off for foul on Alli (81).

Referee: Lee Mason.